RVs can be either motor vehicles or towable trailers, and may be used for leisure activities such as camping and/or vacations. They may be found in RV parks or campgrounds, and can be rented in most major cities and tourist areas. They are occasionally used as mobile offices for business travelers, and in those instances may include customizations such as extra desk space, an upgraded electrical system, a generator, and satellite Internet. Other RVs serve as traveling permanent homes.